Capacitance detection module, method and electronic device

ABSTRACT

The present application provides a capacitance detection module, a method and an electronic device, including: a sensing module and detecting circuit; a first sensing unit is disposed on the first surface of the sensing module, and a second sensing unit is disposed on the second surface of the sensing module; the first sensing unit and the second sensing unit are respectively connected to the detecting circuit; the detecting circuit is configured to determine, according to the capacitance value of the first sensing unit and the capacitance value of the second sensing unit, the wearing state of the user to the device having the capacitance detection module. Thereby the problem that the capacitance detection is affected by temperature is avoided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of the International Application No.PCT/CN2018/109204, filed on Sep. 30, 2018, entitled “CAPACITANCEDETECTION MODULE, METHOD AND ELECTRONIC DEVICE”, the content of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to the field of capacitance detectiontechnology and, in particular, to a capacitance detection module, amethod and an electronic device.

BACKGROUND

With the development of technology, electronic devices are becoming moreand more intelligent. For example, there is a kind of earphone in themarket, when a user puts the earphone into the ear or removes theearphone, the earphone can automatically sense, that is, when the userputs the earphone, music could be played automatically, and the musiccould be paused when the user removes the earphone. This detectingprinciple could be implemented based on a capacitance detection module.

Specifically, FIG. 1 is a schematic diagram of a capacitance detectionmodule 10 provided by the prior art. As shown in FIG. 1, the capacitancedetection module 10 includes: a sensing module 11 (which may be aflexible printed circuit board (FPC)) and a detecting circuit 12. Theupper surface of the sensing module 11 is provided with a sensor 13, thelower surface of the sensing module 11 is provided with a ground unit(GND) 14, and a dielectric layer 15 could be disposed between the sensor13 and the ground unit (GND) 14. When a human body approaches the sensor13, an electric field between the sensor 13 and the ground unit 14changes, thereby the self-capacitance between them also changes. Theself-capacitance refers to the capacitance value between the sensor 13and the ground unit 14. However, in addition to the proximity of thehuman body, the change in temperature may also affect the capacitancevalue, for example, the temperature may cause the dielectric layer 15and the sensor 13 on the sensing module 11 to expand or contract. Theeffect of temperature on the capacitance value could be calledtemperature drift. In practical applications, the effect of temperaturedrift on the capacitance value even exceeds the change of thecapacitance value when the human body approaches. For example, a rapidchange in temperature causes the detecting circuit 12 to recognize thatthe user is wearing a device with such detecting circuit, but in factthe user does not wear the device at this time, or the change intemperature causes the detecting circuit 12 to recognize that the userhas removed the device, but in fact the user does not remove the deviceat this time. Based on this, the prior art has a problem that thecapacitance detection is affected by temperature.

SUMMARY

The present application provides a capacitance detection module, amethod and an electronic device, thereby avoiding the problem that thecapacitance detection is affected by temperature.

In a first aspect, the present application provides a capacitancedetection module, including: a sensing module and a detecting circuit; afirst sensing unit is disposed on a first surface of the sensing module,and a second sensing unit is disposed on a second surface of the sensingmodule; the first sensing unit and the second sensing unit arerespectively connected to the detecting circuit; and the detectingcircuit is configured to determine, according to a capacitance value ofthe first sensing unit and a capacitance value of the second sensingunit, a wearing state of a device having the capacitance detectionmodule.

In a second aspect, the present application provides a capacitancedetection method, the method is applied to a capacitance detectionmodule, and the capacitance detection module includes: a sensing moduleand a detecting circuit; a sensing module and a detecting circuit; afirst sensing unit is disposed on a first surface of the sensing module,and a second sensing unit is disposed on a second surface of the sensingmodule; the first sensing unit and the second sensing unit arerespectively connected to the detecting circuit; and accordingly, themethod includes: determining, according to a capacitance value of thefirst sensing unit and a capacitance value of the second sensing unit,the wearing state of a device having the capacitance detection module.

The present application provides a capacitance detection module, amethod, and an electronic device. Since a second sensing unit is addedto the capacitance detection module, a first sensing unit and the secondsensing unit are simultaneously affected by temperature, but the secondsensing unit does not directly touch a human skin, so when a user wearsthe electronic device with the capacitance detection module, thecapacitance value of the first sensing unit reflects influence oftemperature and touch of the human skin, and the capacitance value ofthe second sensing unit only reflects the influence of the temperature,based on this, a wearing state of the device having the capacitancedetection module could be determined according to the capacitance valuesof the first sensing unit and the second sensing unit, that is, thetechnical solution provided by the embodiment of the present applicationcan avoid a problem that the capacitance detection is affected bytemperature.

BRIEF DESCRIPTION OF DRAWINGS

In order to illustrate the embodiments of the present application or thetechnical solutions in the prior art more clearly, a description of thedrawings used in the embodiments or the prior art description will bebriefly described below. It is obviously that the drawings described inthe following are a certain embodiment of the present application, andother drawings could be obtained according to the drawings without anycreative labor for those skilled in the art.

FIG. 1 is a schematic diagram of a capacitance detection module 10provided by the prior art;

FIG. 2 is a schematic diagram that a capacitance value changes with aninfluence of wearing and temperature provided by the prior art;

FIG. 3 is a schematic diagram of a capacitance detection module 30provided by an embodiment of the present application;

FIG. 4 is a schematic diagram that the capacitance value changes withthe influence of the wearing and temperature provided by the presentapplication;

FIG. 5 is a schematic diagram of changes of R_(n), before and afterwearing of the device provided by an embodiment of the presentapplication;

FIG. 6 is a schematic diagram of a capacitance detection module 60provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a capacitance detection module 70provided by another embodiment of the present application;

FIG. 8 is a schematic diagram of a capacitance detection module 80provided by another embodiment of the present application;

FIG. 9 is a driving timing diagram of a first sensing unit and a secondsensing unit;

FIG. 10 is a flowchart of a capacitance detection method provided by anembodiment of the present application;

FIG. 11 is a flowchart of a capacitance detection method provided byanother embodiment of the present application;

FIG. 12 is a flowchart of a capacitance detection method provided by anembodiment of the present application; and

FIG. 13 is a flowchart of a capacitance detection method provided byanother embodiment of the present application.

DESCRIPTION OF EMBODIMENTS

The technical solution of the present application is hereinafterdescribed in detail with reference to the accompanying drawings. It isevident that the embodiments are only some exemplary embodiments of thepresent application, but not all the embodiments. Other embodiments thatthose skilled in the art obtain based on embodiments of the presentapplication also all within the protection scope of the presentapplication.

The terms “first”, “second”, and the like (if any) in the specification,claims and the above figures of the present application are used todistinguish similar objects, and are not necessarily used to describe aparticular order or a precedence order. It is to be understood that dataused in such case may be interchanged as appropriate, such that theembodiments of the present application described herein could beimplemented, for example, in a sequence other than those illustrated ordescribed herein. In addition, the terms “includes” and “comprises” andany variations of them are intended to cover a non-exclusive inclusion,for example, a process, method, system, product, or device thatcomprises a series of steps or units is not necessarily limited tolisting these steps or units, but may include other steps or units thatnot explicitly listed, or that inherent to such processes, methods,products or devices.

Generally, the capacitance detection module is disposed in an electronicdevice such as a headphone. FIG. 2 is a schematic diagram thatcapacitance values changes with wearing and temperature provided by theprior art. As shown in FIG. 2, the abscissa represents the number ofsampling times, for example, n indicates the n-th sampling, and theordinate represents the capacitance value. When a user does not wear theabove electronic device, the temperature is at 25 degrees Celsius, sincethe temperature is stable and the user has not worn the electronicdevice at this time, the capacitance value is in a stable state; whenthe user is wearing the electronic device, the capacitance valuedecreases due to the proximity of the human body and the change oftemperature, when the user has worn the electronic device, thecapacitance value will first decrease due to the temperature change oftemperature from 25 degrees Celsius to 37 degrees Celsius, and when thetemperature reaches 37 degrees Celsius, the capacitance value is in astable state. It should be noted that, assuming that the electronicdevice is an earphone, when the user is wearing the earphone, the userwill first press the earphone to the ear, so the capacitance value firstdrops to the lowest point, and when the user releases the hand, theearphone will be away from the ear, thus the capacitance value will riseat that moment.

In summary, as mentioned above, an effect of temperature drift on thecapacitance value even exceeds the change in capacitance value when thehuman body approaches in practical applications. For example, a rapidchange of temperature causes the detecting circuit to recognize that theuser has worn a device having such a detecting circuit, but in fact theuser does not wear the device at this time, or the change of temperaturecauses the detecting circuit to recognize that the user has removed thedevice, but in fact, the user did not remove the above device at thistime. The prior art has a problem that the capacitance detection isaffected by temperature. In order to solve the technical problem, thepresent application provides a capacitance detection module, a method,and an electronic device.

The embodiment of the present application provides a capacitancedetection module, including: a sensing module and a detecting circuit; afirst sensing unit is disposed on a first surface of the sensing module,and a second sensing unit is disposed on a second surface of the sensingmodule; the first sensing unit and the second sensing unit arerespectively connected to the detecting circuit. The detecting circuitis configured to determine, according to a capacitance value of thefirst sensing unit and a capacitance value of the second sensing unit, awearing state of a device having the capacitance detection module.

In an embodiment, the sensing module may be a printed circuit board(PCB), and further, may be a flexible printed circuit board (FPC).

In an embodiment, the first sensing unit is also referred to a sensor orsensing area, and the second sensing unit is also referred to as asensor or sensing area.

Further, the first surface of the sensing module is a surface thattouches with the human body, and the second surface of the sensingmodule is a surface that does not touch with the human body.

Example I

The first sensing unit is not directly opposite to the second sensingunit; the capacitance of the first sensing unit is a self-capacitancevalue between the first sensing unit and a ground, and the capacitanceof the second sensing unit is a self-capacity value between the secondsensing unit and the ground.

Where, it is assumed that the device having the capacitance detectionmodule is horizontally placed, based on this, the so-called “the firstsensing unit is not directly opposite to the second sensing unit” meansthere is a spacing between the first induction unit and the secondinduction unit in the horizontal direction. Further, the ground may bedisposed on the capacitance detection module, for example, may bedisposed on the back of the FPC, or may be disposed on a system circuitboard that is far away. It is not limited in embodiments of the presentapplication.

The detecting circuit is specifically configured to: collect firstreference capacitance between the first sensing unit and the ground, andsecond reference capacitance between the second sensing unit and theground, where the first reference capacitance and the second referencecapacitance are collected when the device having the capacitancedetection module is not worn by the user; then collect first capacitancebetween the first sensing unit and the ground, and second capacitancebetween the second sensing unit and the ground, calculate a differenceof the first capacitance and the first reference capacitance to obtainfirst capacitance difference, and calculate a difference of the secondcapacitance and the second reference capacitance to obtain secondcapacitance difference; and determine, according to the firstcapacitance difference and the second capacitance difference, thewearing state of the device having the capacitance detection module.

In an embodiment, the detecting circuit is specifically configured toobtain a capacitance variation of the first sensing unit caused by humanskin touch by calculating a product of the second capacitance differenceand a preset coefficient and then calculating a difference between thefirst capacitance difference and the product. The preset coefficient isa ratio of the first capacitance difference to the second capacitancedifference when the device is not worn based on a same temperature. Thenthe wearing state of the user to the device having the capacitancedetection module is determined according to the capacitance variation.

Further, the detecting circuit is specifically configured to determinethat the device is not worn by user the if the capacitance variation isgreater than or equal to a first preset threshold; and determine thatthe device has been worn by the user if the capacitance variation issmaller than or equal to a second preset threshold; where the secondpreset threshold is smaller than the first preset threshold.

Specifically, the principle of the Example I is as follows: both thehuman skin touch and the temperature increase will cause the capacitancevalue of the sensing unit to change, and the first sensing unit and thesecond sensing unit are simultaneously affected by temperature, but thehuman skin does not directly touch the second sensing unit, when theuser wears the electronic device, the capacitance variation between thefirst sensing unit and the ground includes a capacitance variationcaused by both the human skin touch and temperature increase, and thecapacitance variation between the second sensing unit and the groundincludes only the capacitance variation caused by an increase intemperature, and the difference between the two can indicate thecapacitance variation caused by human skin touch. The same is true whenthe user removes the electronic device. Therefore, the wearing state ofthe user to the device having the capacitance detection module could bedetermined by the capacitance variation of the first sensing unit causedby touch. Further, the capacitance variation generated by the firstsensing unit and the second sensing unit under the influence of thetemperature may be referred to as a common mode signal, and thecapacitance variation of the first sensing unit and the second sensingunit when touched by human skin may be referred to as a differentialmode signal.

FIG. 4 is a schematic diagram that the capacitance value changes withthe influence of the wearing and temperature provided by the presentapplication, and as shown in FIG. 4, the abscissa represents the numberof sampling times, for example, n represents the n-th sampling, and theordinate represents the capacitance value. The solid line indicates thechange in capacitance between the first sensing unit and the ground, andthe broken line indicates the change in capacitance between the secondsensing unit and the ground, and as shown in FIG. 4, when a user doesnot wear the above-mentioned electronic device, the temperature is at 25degrees Celsius, since the temperature is stable at this time, and theuser has not worn the electronic device, the capacitance value betweenthe first sensing unit and the ground is in a stable state, when theuser is wearing the electronic device, the capacitance value decreasesdue to the proximity of the human body and the change of temperature,and when the user has worn the electronic device, the capacitance valuewill first decrease due to the temperature change of temperature from 25degrees Celsius to 37 degrees Celsius, and when the temperature reaches37 degrees Celsius, the capacitance value is in a stable state. When theuser does not wear the above-mentioned electronic device, thetemperature is at 25 degrees Celsius, since the temperature is stableand the user has not worn the electronic device at this time, thecapacitance value between the second sensing unit and the ground is in astable state, when the user is wearing the electronic device, since thetemperature is still at 25 degrees Celsius and is not affected by humanskin touch, so the capacitance value between the second sensing unit andthe ground remains stable, and when the user has worn the electronicdevice, the capacitance value will first decrease due to the temperaturechange of temperature from 25 degrees Celsius to 37 degrees Celsius, andwhen the temperature reaches 37 degrees Celsius, the capacitance valueis in a stable state.

The following describes the specific calculation manner of thecapacitance variation R_(n) of the first sensing unit caused by touch:R _(n)=(Sensor_(n)−Sensor₁)−K*(Ref_(n)−Ref₁)

Where, Sensor₁ represents first reference capacitance, Sensor_(n)represents first capacitance between the first sensing unit and theground, Ref₁ represents second reference capacitance, and Ref_(n)represents second capacitance between the second sensing unit and theground, K represents the preset coefficient.

FIG. 5 is a schematic diagram of changes of R_(n) before and afterwearing the device provided by an embodiment of the present application,and as shown in FIG. 5, after the second sensing unit is added, theinfluence of temperature on capacitance detection is eliminated, and ifthe capacitance variation R_(n), is less than or equal to a secondpreset threshold, it is determined that the device has been worn by auser; at this time, the earphone performs further operations, such asplaying music and the like. Accordingly, if the capacitance variationR_(n), is greater than or equal to a first preset threshold, it isdetermined that the device is not worn by the user; at this time, theearphone performs further operations, such as pause music and the like.Where, the second preset threshold is smaller than the first presetthreshold. If the capacitance variation R_(n), is between the firstpreset threshold and the second preset threshold, the judgment is madein conjunction with the wearing state at the previous moment, which isthe same as the wearing state at the previous moment.

Example II

FIG. 3 is a schematic diagram of a capacitance detection module 30provided by an embodiment of the present application, and as shown inFIG. 3, the capacitance detection module 30 includes: a sensing module31 and a detecting circuit 32; a first sensing unit 33 and a firstground unit 34 are disposed on the first surface of the sensing module31, and a second sensing unit 35 and a second ground unit 36 aredisposed on the second surface of the sensing module 31; where, thefirst sensing unit 33 is directly opposite to the second ground unit 36,and the second sensing unit 35 is directly opposite to the first groundunit 34. Based on this, the capacitance value of the first sensing unit33 is a self-capacitance value of the first sensing unit 33 to thesecond ground unit 36, and the capacitance value of the second sensingunit is a self-capacitance of the second sensing unit 35 to the firstground unit 34. Further, the first sensing unit 33 and the secondsensing unit 35 are respectively connected to a detecting circuit 32. Inan embodiment, the first sensing unit 33 is also referred to as a sensoror sensing area, and the second sensing unit 35 is also referred to as asensor or sensing area.

In an embodiment, the first ground unit 34 and the second ground unit 36are connected to the same ground, which may be understood as twodifferent regions on the sensing module 31.

In an embodiment, a dielectric layer 37 is disposed between the firstsensing unit 33 and the second ground unit 36, and the dielectric layer37 may be a polyimide film or air, and similarly, a dielectric layer 37is disposed between the second sensing unit 35 and the first ground unit34, and the dielectric layer 37 may be a polyimide film or air.

The detecting circuit 32 is specifically configured to: collect firstreference capacitance of the first sensing unit 33 to the ground, andsecond reference capacitance of the second sensing unit 35 to theground; collect first capacitance of the first sensing unit 33 to theground, and second capacitance of the second sensing unit 35 to theground, calculate a difference between the first capacitance and thefirst reference capacitance to obtain first capacitance difference, andcalculate a difference between the second capacitance and the secondreference capacitance to obtain second capacitance difference; anddetermine, according to the first capacitance difference and the secondcapacitance difference, the wearing state of the device having thecapacitance detection module.

In an embodiment, the detecting circuit 32 is specifically configured toobtain a capacitance variation of the first sensing unit caused by touchby calculating a product of the second capacitance difference and thepreset coefficient and then calculating a difference between the firstcapacitance difference and the product, the preset coefficient is aratio of the first capacitance difference to the second capacitancedifference when the device is not worn based on a same temperature; anddetermine, according to the capacitance variation, the wearing state ofa user to the device having the capacitance detection module.

Further, the detecting circuit 32 is specifically configured todetermine that the device is not worn by user the if the capacitancevariation is greater than or equal to a first preset threshold; anddetermine that the device has been worn by the user if the capacitancevariation is smaller than or equal to a second preset threshold; wherethe second preset threshold is smaller than the first preset threshold.If the capacitance variation is between the first preset threshold andthe second preset threshold, it is determined in conjunction with thewearing state of the previous moment, which is the same as the wearingstate at the previous moment.

The principle of Example II and the calculation manner of thecapacitance variation are the same as those in Example I, which are notdescribed herein again.

In an embodiment, FIG. 6 is a schematic diagram of a capacitancedetection module 60 provided by an embodiment of the presentapplication, and as shown in FIG. 6, the detecting circuit 32 includes afirst amplifier 61 and a first capacitor 62, and the first capacitor 62is connected to the first amplifier 61, and the first amplifier 61 isconnected to the first sensing unit 33. The capacitance detection modulefurther includes: a second amplifier 63 and a second capacitor 64, thesecond capacitor 64 is connected to the second amplifier 63, and thesecond amplifier 63 is connected to the second sensing unit 35.

It should be noted that the structure of the detecting circuit is notlimited to that shown in FIG. 6.

Example III

The embodiments of the present application further provide a capacitancedetection module, where the first sensing unit is directly opposite tothe second sensing unit, and the area of the first sensing unit is thesame as the area of the second sensing unit; the capacitance value ofthe first sensing unit is the self-capacitance value between the firstsensing unit and the ground, and the capacitance value of the secondsensing unit is the self-capacitance value between the second sensingunit and the ground. The ground may be disposed on the capacitancedetection module, for example, may be disposed on the back of the FPC oron the system board that is far away. It is not limited in embodimentsof the present application.

In this case, the first sensing unit and the second sensing unit couldbe simultaneously driven, that is, the first sensing unit and the secondsensing unit can maintain the same voltage (0V or driving voltage) atany time, and at this time, since the voltage difference between the twoΔU=0, there is no transfer of charge between the two, both refer to thedistant ground, but similarly, because they are affected by temperaturesimilarly, they also have the ability to suppress temperature.

In an embodiment, the first sensing unit is also referred to as a sensoror sensing area, and the second sensing unit is also referred to as asensor or sensing area.

The detecting circuit is specifically configured to: collect firstreference capacitance between the first sensing unit and the ground, andsecond reference capacitance between the second sensing unit and theground; collect first capacitance between the first sensing unit and theground, and second capacitance between the second sensing unit and theground, calculate a difference between the first capacitance and thefirst reference capacitance to obtain first capacitance difference, andcalculate a difference between the second capacitance and the secondreference capacitance to obtain second capacitance difference; anddetermine, according to the first capacitance difference and the secondcapacitance difference, the wearing state of the device having thecapacitance detection module.

In an embodiment, the detecting circuit is specifically configured toobtain a capacitance variation of the first sensing unit caused by touchby calculating a product of the second capacitance difference and thepreset coefficient and then calculating a difference between the firstcapacitance difference and the product, the preset coefficient is aratio of the first capacitance difference to the second capacitancedifference when the device is not worn based on a same temperature; anddetermine, according to the capacitance variation, the wearing state ofthe user to the device having the capacitance detection module.

Further, the detecting circuit is specifically configured to determinethat the device is not worn by user the if the capacitance variation isgreater than or equal to a first preset threshold; and determine thatthe device has been worn by the user if the capacitance variation issmaller than or equal to a second preset threshold; where the secondpreset threshold is smaller than the first preset threshold. If thecapacitance variation is between the first preset threshold and thesecond preset threshold, it is determined in conjunction with thewearing state of the previous moment, which is the same as the wearingstate at the previous moment.

The principle of Example III and the calculation manner of thecapacitance variation are the same as those in Example I and Example II,which are not described herein again.

In summary, in Example I, Example II or Example III, since a secondsensing unit is added to the capacitance detection module, a firstsensing unit and the second sensing unit are simultaneously affected bytemperature, but the second sensing unit does not directly touch thehuman skin, so when the user wears the electronic device, thecapacitance value of the first sensing unit reflects influence oftemperature and touch of the human skin, and the capacitance value ofthe second sensing unit only reflects the influence of the temperature,based on this, a wearing state of the device having the capacitancedetection module could be determined according to the capacitance valuesof the first sensing unit and the second sensing unit, that is, thetechnical solution provided by the embodiment of the present applicationcan avoid a problem that the capacitance detection is affected bytemperature.

Example IV

FIG. 7 is a schematic diagram of a capacitance detection module 70provided by another embodiment of the present application, and as shownin FIG. 7, the capacitance detection module 70 includes: a sensingmodule 71, a changeover switch 72, a detecting circuit 73; a firstsensing unit 74 is disposed on a first surface of the sensing module 71,and a second sensing unit 75 is disposed on a second surface of thesensing module 71. Where the first sensing unit 74 is directly oppositeto the second sensing unit 75, and the first sensing unit 74 has thesame area as the second sensing unit 75. Based on this, the capacitancevalue of the first sensing unit 74 is the self-capacitance value of thefirst sensing unit 74 to the second sensing unit 75 which is grounded,and the capacitance value of the second sensing unit 75 is theself-capacitance value of the second sensing unit 75 to the firstsensing unit 74 which is grounded.

The changeover switch 72 is configured to perform an alternate switchingbetween a first state and a second state of the state of the sensingmodule 71. The first state is that the first sensing unit 74 isrespectively connected to a driving voltage output by the detectingcircuit 73 and a sensing channel of the detecting circuit 73, and thesecond sensing unit 75 is connected to the ground; the second state isthat the second sensing unit 75 is respectively connected to drivingvoltage output by the detecting circuit 73 and the sensing channel ofthe detecting circuit 73, the first sensing unit 74 is connected to theground.

The detecting circuit 73 is specifically configured to: collect firstreference capacitance between the first sensing unit 74 and the secondsensing unit 75 in the first state, and second reference capacitancebetween the second sensing unit 75 and the first sensing unit 74 in thesecond state; collect first capacitance between the first sensing unit74 and the second sensing unit 75 in the first state, and secondcapacitance between the second sensing unit 75 and the first sensingunit 74 in the second state, calculate a difference between the firstcapacitance and the first reference capacitance to obtain firstcapacitance difference, and calculate a difference between the secondcapacitance and the second reference capacitance to obtain secondcapacitance difference; calculate a difference between the firstcapacitance difference and the second capacitance difference to obtainthe capacitance variation of the first sensing unit caused by touch; anddetermine, according to the capacitance variation, the wearing state ofthe device having the capacitance detection module.

Further, the detecting circuit 73 is specifically configured to:determine that the device is not worn by user the if the capacitancevariation is greater than or equal to a first preset threshold; anddetermine that the device has been worn by the user if the capacitancevariation is smaller than or equal to a second preset threshold; wherethe second preset threshold is smaller than the first preset threshold.If the capacitance variation is between the first preset threshold andthe second preset threshold, it is determined in conjunction with thewearing state of the previous moment, which is the same as the wearingstate at the previous moment.

In an embodiment, the sensing module 71 may be a PCB, and further, maybe a flexible printed circuit board (FPC).

In an embodiment, the first sensing unit 74 is also referred to as asensor or sensing area, and the second sensing unit 75 is also referredto as a sensor or sensing area.

In an embodiment, a dielectric layer 76 is disposed between the firstsensing unit 74 and the second sensing unit 75, and the dielectric layer76 may be a polyimide film.

FIG. 8 is a schematic diagram of a capacitance detection module 80provided by another embodiment of the present application, and as shownin FIG. 8, the changeover switch 72 is configured to make the firstsensing unit 74 and the second sensing unit 75 be alternately driven,and when the first sensing unit 74 is connected to the detecting circuit73 through the S1 in the changeover switch 72, the first sensing unit 74is driven, at this time, the second sensing unit 75 is a GND, and whenthe second sensing unit 75 is connected to the detecting circuit 73through the S2 in the changeover switch 72, the second sensing unit 75is driven, and the first sensing unit 74 is a GND. FIG. 9 is a drivingtiming chart of the first sensing unit and the second sensing unit, andas shown in FIG. 9, the first sensing unit and the second sensing unitare alternately driven.

Further, as shown in FIG. 8, the detecting circuit 73 includes anamplifier 77 and a capacitor 78.

Compared with the technical solution provided in Example I, Example IIand Example III, the GND of the technical solution provided in ExampleIV is dynamic changing, that is, the GND is on the lower surface of thesensing module when the first sensing unit is driven, based on this, thechange of capacitance caused by human skin touch and temperature risewhen the user wears the device could be sensed, and the GND is on theupper surface of the sensing module when the second sensing unit isdriven, and only the change of capacitance caused by the temperaturerise when the user wears the device could be sensed. The capacitancevariation R_(n), of the first sensing unit caused by touch is calculatedby the following formula.R _(n)=(Sensor_(n)−Sensor₁)−(Ref_(n)−Ref₁)

Where, Sensor₁ represents first reference capacitance, Sensor_(n)represents first capacitance between the first sensing unit and thesecond sensing unit in the first state, and Ref₁ represents secondreference capacitance, and Ref_(n) represents second capacitance betweenthe first sensing unit and the second sensing unit in the second state.

In summary, in Example IV, the first sensing unit and the second sensingunit are simultaneously affected by temperature, but the second sensingunit does not directly touch human skin, so when the user wears theelectronic device, the capacitance variation between the first sensingunit and the second sensing unit in the first state reflects theinfluence of temperature and the touch of human skin, and thecapacitance variation between the second sensing unit and the firstsensing unit in the second state only reflects the influence oftemperature, therefore, in the embodiments of the present application,the wearing state of the user to the device with capacitance detectionmodule could be determined by the capacitance value of the first sensingunit and the second sensing unit in the first state and the capacitancevalue of the second sensing unit and the first sensing unit in thesecond state, that is, the technical solution provided by theembodiments of the present application can avoid the problem that thecapacitance detection is affected by temperature.

Example V

The embodiments of the present application further provide a capacitancedetection module, where a first sensing unit is directly opposite to asecond sensing unit, and the area of the first sensing unit is the sameas the area of the second sensing unit, and the capacitance of the firstsensing unit is a mutual capacitance value between the first sensingunit and the second sensing unit in a third state, and the capacitancevalue of the second sensing unit is a mutual capacitance value betweenthe first sensing unit and the second sensing unit in a fourth state;where the third state is that the first sensing unit is connected to adriving voltage output by the detecting circuit, and the second sensingunit is connected to a sensing channel of the detecting circuit; wherethe fourth state is that the second sensing unit is connected to thedriving voltage output by the detecting circuit, and the first sensingunit is connected to the sensing channel of the detecting circuit.

The detecting circuit further includes a changeover switch, and theswitching switch is configured to perform an alternate switching betweenthe third state and the fourth state of the state of the sensing module;

The detecting circuit is specifically configured to: collect firstreference capacitance between the first sensing unit and the secondsensing unit in the third state, and second reference capacitancebetween the second sensing unit and the first sensing unit in the secondstate; collect first capacitance between the first sensing unit and thesecond sensing unit in the fourth state, and second capacitance betweenthe second sensing unit and the first sensing unit in the second state,calculate a difference between the first capacitance and the firstreference capacitance to obtain first capacitance difference, andcalculate a difference between the second capacitance and the secondreference capacitance to obtain second capacitance difference; calculatea difference between the first capacitance difference and the secondcapacitance difference to obtain a capacitance variation touch of thefirst sensing unit caused by touch; and determine, according to thecapacitance variation, the wearing state of the device having thecapacitance detection module.

In an embodiment, the detecting circuit is specifically configured to:determine that the device is not worn by user the if the capacitancevariation is greater than or equal to a first preset threshold; anddetermine that the device has been worn by the user if the capacitancevariation is smaller than or equal to a second preset threshold; wherethe second preset threshold is smaller than the first preset threshold.If the capacitance variation is between the first preset threshold andthe second preset threshold, it is determined in conjunction with thewearing state of the previous moment, which is the same as the wearingstate at the previous moment.

In an embodiment, the sensing module may be a PCB, and further, may be aflexible printed circuit board (FPC).

In an embodiment, the first sensing unit is also referred to as a sensoror sensing area, and the second sensing unit is also referred to as asensor or sensing area.

In an embodiment, a dielectric layer is disposed between the firstsensing unit and the second sensing unit, and the dielectric layer maybe a polyimide film.

The capacitance variation R_(n) of the first sensing unit caused bytouch is calculated by the following formula.R _(n)=(Sensor_(n)−Sensor₁)−(Ref_(n)−Ref₁)

Where, Sensor₁ represents first reference capacitance, and Sensor_(n)represents first capacitance between the first sensing unit and thesecond sensing unit in the third state, and Ref₁ represents the secondreference capacitance, and Ref_(n) represents second capacitance betweenthe first sensing unit and the second sensing unit in the fourth state.

In summary, in Example V, the first sensing unit and the second sensingunit are simultaneously affected by temperature, but the second sensingunit does not directly touch human skin, so when the user wears theelectronic device, the capacitance variation between the first sensingunit and the second sensing unit in the third state reflects theinfluence of temperature and the touch of human skin, and thecapacitance variation between the first sensing unit and the secondsensing unit in the fourth state only reflects the influence oftemperature, therefore, in the embodiments of the present application,the wearing state of the user to the device having the capacitancedetection module could be determined by the capacitance value of thefirst sensing unit and the second sensing unit in the third state andthe capacitance value of the second sensing unit and the first sensingunit in the fourth state, that is, the technical solution provided bythe embodiments of the present application can avoid the problem thatthe capacitance detection is affected by temperature.

A capacitance detection method is provided by an embodiment of thepresent application, the method is applied to a capacitance detectionmodule, which includes a sensing module and a detecting circuit; a firstsensing unit is disposed on the first surface of the sensing module, anda second sensing unit is disposed on a second surface of the secondsensing module; the first sensing unit and the second sensing unit arerespectively connected to the detecting circuit; the capacitance valueof the first sensing unit is a self-capacitance value between the firstsensing unit and the ground, and the capacitance value of the secondsensing unit is the self-capacitance value between the second sensingunit and the ground. Accordingly, the method includes: the detectingcircuit determines the wearing state of the user to the device havingthe capacitance detection module according to the capacitance value ofthe first sensing unit and the capacitance value of the second sensingunit.

Optional Method I:

FIG. 10 is a flowchart of a capacitance detection method provided by anembodiment of the present application, which is based on theabove-mentioned capacitance detection module provided by Example I,Example II or Example III, accordingly, as shown in FIG. 10, thedetecting circuit determines the wearing state of a user to the devicehaving the capacitance detection module according to the capacitancevalue of the first sensing unit and the capacitance value of the secondsensing unit, includes the following steps:

Step S101: collecting first reference capacitance between the firstsensing unit and the ground, and second reference capacitance betweenthe second sensing unit and the ground.

Step S102: collecting first capacitance between the first sensing unitand the ground, and second capacitance between the second sensing unitand the ground, calculating a difference between the first capacitanceand the first reference capacitance to obtain first capacitancedifference, and calculating a difference between the second capacitanceand the second reference capacitance to obtain second capacitancedifference.

Step S103: determining, according to the first capacitance differenceand the second capacitance difference, the wearing state of the user tothe device having the capacitance detection module.

In an embodiment, FIG. 11 is a flowchart of a capacitance detectionmethod provided by another embodiment of the present application, and asshown in FIG. 11, the step S103 includes the following steps:

Step S111: calculating a product of the second capacitance differenceand the preset coefficient, and calculating a difference between thefirst capacitance difference and the product to obtain a capacitancevariation of the first sensing unit caused by touch, where the presetcoefficient being a ratio of the first capacitance difference to thesecond capacitance difference when the device is not worn based on asame temperature.

Step S112: determine, according to the capacitance variation, thewearing state of the user to the device having the capacitance detectionmodule.

Where, if the capacitance variation is greater than or equal to a firstpreset threshold, determining that the device is not worn by the user;if the capacitance variation is less than or equal to a second presetthreshold, determining that the device has been worn by the user; wherethe second preset threshold is less than the first preset threshold. Ifthe capacitance variation is between the first preset threshold and thesecond preset threshold, it is determined in conjunction with thewearing state of the previous moment, which is the same as the wearingstate at the previous moment.

The capacitance detection method provided by the embodiments of thepresent application may be executed by the capacitance detection moduleof Example I, Example II, or Example III, the content and effect thereofmay refer to Example I, Example II, or Example III, which are notdescribed herein again.

FIG. 12 is a flowchart of a capacitance detection method provided by anembodiment of the present application, the method is applied to thecapacitance detection module provided in Example IV, and accordingly, asshown in FIG. 12, the detecting circuit determines the wearing state ofthe user to the device having the capacitance detection module accordingto the capacitance value of the first sensing unit and the capacitancevalue of the second sensing unit, includes the following steps:

Step S121: collecting first reference capacitance between the firstsensing unit and the second sensing unit in the first state, and secondreference capacitance between the second sensing unit and the firstsensing unit in the second state.

Step S122: collecting first capacitance between the first sensing unitand the second sensing unit in the first state, and second capacitancebetween the second sensing unit and the first sensing unit in the secondstate, calculating a difference between the first capacitance and thefirst reference capacitance to obtain first capacitance difference, andcalculating a difference between the second capacitance and the secondreference capacitance to obtain second capacitance difference.

Step S123: calculating a difference between the first capacitancedifference and the second capacitance difference to obtain a capacitancevariation of the first sensing unit caused by touch.

Step S124: determining, according to the capacitance variation, thewearing state of the user to the device having the capacitance detectionmodule.

Where, if the capacitance variation is greater than or equal to a firstpreset threshold, determining that the device is not worn by the user;if the capacitance variation is less than or equal to a second presetthreshold, determining that the device has been worn by the user; wherethe second preset threshold is less than the first preset threshold.

The capacitance detection method provided by the embodiments of thepresent application may be executed by the capacitance detection moduleof Example IV, the content and effect thereof may refer to Example IV,which are not described herein again.

FIG. 13 is a flowchart of a capacitance detection method provided byanother embodiment of the present application, the method is applied tothe capacitance detection module provided in Example V, and accordingly,as shown in FIG. 13, the detecting circuit determines the wearing stateof a user to the device having the capacitance detection moduleaccording to the capacitance value of the first sensing unit and thecapacitance value of the second sensing unit, includes the followingsteps:

Step S131: collecting first reference capacitance between the firstsensing unit and the second sensing unit in the third state, and secondreference capacitance between the second sensing unit and the firstsensing unit in the fourth state;

Step S132: collecting first capacitance between the first sensing unitand the second sensing unit in the third state, and second capacitancebetween the second sensing unit and the first sensing unit in the fourthstate, calculating a difference between the first capacitance and thefirst reference capacitance to obtain first capacitance difference, andcalculating a difference between the second capacitance and the secondreference capacitance to obtain second capacitance difference;

Step S133: calculating a difference between the first capacitancedifference and the second capacitance difference to obtain a capacitancevariation of the first sensing unit caused by touch.

Step S134: determining, according to the capacitance variation, thewearing state of the user to the device having the capacitance detectionmodule.

The capacitance detection method provided in the embodiments of thepresent application may be executed by the capacitance detection moduleof Example V, the content and effect thereof may refer to the Example V,which are not described herein again.

The present application further provides an electronic device, theelectronic device includes the capacitance detection module of ExampleI, Example II, Example III, Example IV, or Example V. In an embodiment,the electronic device may be an earphone.

Since the electronic device provided by the embodiments of the presentapplication includes Example I, Example II, Example III, Example IV, orExample V, and the content and effect thereof may refer to Example I,Example II, Example III, Example IV, or Example V, which are notdescribed herein again.

What is claimed is:
 1. A capacitance detection module, comprising: asensing module and a detecting circuit; a first sensing unit is disposedon a first surface of the sensing module, and a second sensing unit isdisposed on a second surface of the sensing module; the first sensingunit and the second sensing unit are respectively connected to thedetecting circuit; the detecting circuit is configured to determine,according to a capacitance value of the first sensing unit and acapacitance value of the second sensing unit, a wearing state of adevice having the capacitance detection module; wherein the firstsensing unit is directly opposite to the second sensing unit, and thearea of the first sensing unit is the same as the area of the secondsensing unit; the capacitance value of the first sensing unit is aself-capacitance value between the first sensing unit and the secondsensing unit which is grounded, the capacitance value of the secondsensing unit is a self-capacitance value between the second sensing unitand the first sensing unit which is grounded; wherein the detectingcircuit further comprises a changeover switch, wherein the changeoverswitch is configured to perform an alternate switching between a firststate and a second state of the state of the sensing module, wherein thefirst state is that the first sensing unit is respectively connected toa driving voltage output by the detecting circuit and a sensing channelof the detecting circuit, and the second sensing unit is connected tothe ground; wherein the second state is that the second sensing unit isrespectively connected to the driving voltage output by the detectingcircuit and the sensing channel of the detecting circuit, and the firstsensing unit is connected to the ground; and the detecting circuit isconfigured to: collect first reference capacitance between the firstsensing unit and the second sensing unit in the first state, and secondreference capacitance between the second sensing unit and the firstsensing unit in the second state; collect first capacitance between thefirst sensing unit and the second sensing unit in the first state, andsecond capacitance between the second sensing unit and the first sensingunit in the second state, calculate a difference of the firstcapacitance and the first reference capacitance to obtain firstcapacitance difference, and calculate a difference of the secondcapacitance and the second reference capacitance to obtain secondcapacitance difference; calculate a difference of the first capacitancedifference and the second capacitance difference to obtain a capacitancevariation of the first sensing unit caused by touch; determine,according to the capacitance variation, the wearing state of the devicehaving the capacitance detection module; or, wherein the first sensingunit is directly opposite to the second sensing unit, and the area ofthe first sensing unit is the same as the area of the second sensingunit, the capacitance value of the first sensing unit is a mutualcapacitance value between the first sensing unit and the second sensingunit, and the capacitance value of the second sensing unit is a mutualcapacitance value between the second sensing unit and the first sensingunit wherein the detecting circuit further comprises a changeoverswitch, wherein the changeover switch is configured to perform analternate switching between a third state and a fourth state of thestate of the sensing module; wherein the third state is that the firstsensing unit is connected to a driving voltage output by the detectingcircuit, and the second sensing unit is connected to a sensing channelof the detecting circuit wherein the fourth state is that the secondsensing unit is connected to the driving voltage output by the detectingcircuit, and the first sensing unit is connected to the sensing channelof the detecting circuit and the detecting circuit is configured to:collect first reference capacitance between the first sensing unit andthe second sensing unit in the third state, and second referencecapacitance between the second sensing unit and the first sensing unitin the fourth state; collect first capacitance between the first sensingunit and the second sensing unit in the third state, and secondcapacitance between the second sensing unit and the first sensing unitin the fourth state, calculate a difference of the first capacitance andthe first reference capacitance to obtain first capacitance difference,and calculate a difference of the second capacitance and the secondreference capacitance to obtain second capacitance difference; calculatea difference of the first capacitance difference and the secondcapacitance difference to obtain a capacitance variation of the firstsensing unit caused by touch; determine, according to the capacitancevariation, the wearing state of the device having the capacitancedetection module.
 2. The module according to claim 1, wherein thedetecting circuit is configured to: determine that the device is notworn if the capacitance variation is greater than or equal to a firstpreset threshold; determine that the device has been worn if thecapacitance variation is smaller than or equal to a second presetthreshold; wherein the second preset threshold is smaller than the firstpreset threshold.
 3. A capacitance detection method, wherein the methodis applied in a capacitance detection module, the capacitance detectionmodule comprising: a sensing module and a detecting circuit; a firstsensing unit is disposed on a first surface of the sensing module, and asecond sensing unit is disposed on a second surface of the sensingmodule; the first sensing unit and the second sensing unit arerespectively connected to the detecting circuit; accordingly, the methodcomprises: determining, according to a capacitance value of the firstsensing unit and a capacitance value of the second sensing unit, thewearing state of a device having the capacitance detection module;wherein the first sensing unit is directly opposite to the secondsensing unit, and the area of the first sensing unit is the same as thearea of the second sensing unit the capacitance value of the firstsensing unit is a self-capacitance value between the first sensing unitand the second sensing unit which is grounded, and the capacitance valueof the second sensing unit is a self-capacitance between the secondsensing unit and the first sensing unit which is grounded; the detectingcircuit further comprises a changeover switch, wherein the changeoverswitch is configured to perform an alternate switching between a firststate and a second state of the state of the sensing module, wherein thefirst state is that the first sensing unit is respectively connected toa driving voltage output by the detecting circuit and a sensing channelof the detecting circuit, and the second sensing unit is connected tothe ground; wherein the second state is that the second sensing unit isconnected to the driving voltage output by the detecting circuit and thesensing channel of the detecting circuit, and the first sensing unitbeing connected to the ground; accordingly, the determining, accordingto a capacitance value of the first sensing unit and a capacitance valueof the second sensing unit, the wearing state of a device having thecapacitance detection module, comprises: collecting first referencecapacitance between the first sensing unit and the second sensing unitin the first state, and second reference capacitance between the secondsensing unit and the first sensing unit in the second state; collectingfirst capacitance between the first sensing unit and the second sensingunit in the first state, and second capacitance between the secondsensing unit and the first sensing unit in the second state, calculatinga difference of the first capacitance and the first referencecapacitance to obtain first capacitance difference, and calculating adifference of the second capacitance and the second referencecapacitance to obtain second capacitance difference; calculating adifference of the first capacitance difference and the secondcapacitance difference to obtain a capacitance variation of the firstsensing unit caused by touch; determining, according to the capacitancevariation, the wearing state of the device having the capacitancedetection module; or, wherein the first sensing unit is directlyopposite to the second sensing unit, and the area of the first sensingunit is the same as the area of the second sensing unit, the capacitancevalue of the first sensing unit is a mutual capacitance value betweenthe first sensing unit and the second sensing unit, and the capacitancevalue of the second sensing unit is a mutual capacitance value betweenthe second sensing unit and the first sensing unit the detecting circuitfurther comprises a changeover switch, wherein the changeover switch isconfigured to perform an alternate switching between a third state and afourth state of the state of the sensing module; wherein the third stateis that the first sensing unit is connected to a driving voltage outputby the detecting circuit, and the second sensing unit is connected to asensing channel of the detecting circuit; wherein the fourth state isthat the second sensing unit is connected to the driving voltage outputby the detecting circuit, and the first sensing unit is connected to thesensing channel of the detecting circuit accordingly, the determining,according to a capacitance value of the first sensing unit and acapacitance value of the second sensing unit, the wearing state of adevice having the capacitance detection module, comprises: collectingfirst reference capacitance between the first sensing unit and thesecond sensing unit in the third state, and second reference capacitancebetween the second sensing unit and the first sensing unit in the fourthstate; collecting first capacitance between the first sensing unit andthe second sensing unit in the third state, and second capacitancebetween the second sensing unit and the first sensing unit in the fourthstate, calculating a difference of the first capacitance and the firstreference capacitance to obtain first capacitance difference, andcalculating a difference of the second capacitance and the secondreference capacitance to obtain second capacitance difference;calculating a difference of the first capacitance difference and thesecond capacitance difference to obtain a capacitance variation of thefirst sensing unit caused by touch; determining, according to thecapacitance variation, the wearing state of the device having thecapacitance detection module.
 4. The method according to claim 3,wherein the determining, according to the capacitance variation, thewearing state of the device having the capacitance detection module,comprises: determining that the device is not worn if the capacitancevariation is greater than or equal to a first preset threshold;determining that the device has been worn if the capacitance variationis smaller than or equal to a second preset threshold; wherein thesecond preset threshold is smaller than the first preset threshold. 5.An electronic device, comprising a capacitance detection module, whereinthe capacitance detection module comprises a sensing module and adetecting circuit, a first sensing unit is disposed on a first surfaceof the sensing module, and a second sensing unit is disposed on a secondsurface of the sensing module; the first sensing unit and the secondsensing unit are respectively connected to the detecting circuit; thedetecting circuit is configured to determine, according to a capacitancevalue of the first sensing unit and a capacitance value of the secondsensing unit, a wearing state of the electronic device; wherein thefirst sensing unit is directly opposite to the second sensing unit, andthe area of the first sensing unit is the same as the area of the secondsensing unit; the capacitance value of the first sensing unit is aself-capacitance value between the first sensing unit and the secondsensing unit which is grounded, the capacitance value of the secondsensing unit is a self-capacitance value between the second sensing unitand the first sensing unit which is grounded; wherein the detectingcircuit further comprises a changeover switch, wherein the changeoverswitch is configured to perform an alternate switching between a firststate and a second state of the state of the sensing module, wherein thefirst state is that the first sensing unit is respectively connected toa driving voltage output by the detecting circuit and a sensing channelof the detecting circuit, and the second sensing unit is connected tothe ground; wherein the second state is that the second sensing unit isrespectively connected to the driving voltage output by the detectingcircuit and the sensing channel of the detecting circuit, and the firstsensing unit is connected to the ground; and the detecting circuit isconfigured to: collect first reference capacitance between the firstsensing unit and the second sensing unit in the first state, and secondreference capacitance between the second sensing unit and the firstsensing unit in the second state; collect first capacitance between thefirst sensing unit and the second sensing unit in the first state, andsecond capacitance between the second sensing unit and the first sensingunit in the second state, calculate a difference of the firstcapacitance and the first reference capacitance to obtain firstcapacitance difference, and calculate a difference of the secondcapacitance and the second reference capacitance to obtain secondcapacitance difference; calculate a difference of the first capacitancedifference and the second capacitance difference to obtain a capacitancevariation of the first sensing unit caused by touch; determine,according to the capacitance variation, the wearing state of theelectronic device; or, wherein the first sensing unit is directlyopposite to the second sensing unit, and the area of the first sensingunit is the same as the area of the second sensing unit, the capacitancevalue of the first sensing unit is a mutual capacitance value betweenthe first sensing unit and the second sensing unit, and the capacitancevalue of the second sensing unit is a mutual capacitance value betweenthe second sensing unit and the first sensing unit wherein the detectingcircuit further comprises a changeover switch, wherein the changeoverswitch is configured to perform an alternate switching between a thirdstate and a fourth state of the state of the sensing module; wherein thethird state is that the first sensing unit is connected to a drivingvoltage output by the detecting circuit, and the second sensing unit isconnected to a sensing channel of the detecting circuit wherein thefourth state is that the second sensing unit is connected to the drivingvoltage output by the detecting circuit, and the first sensing unit isconnected to the sensing channel of the detecting circuit and thedetecting circuit is configured to: collect first reference capacitancebetween the first sensing unit and the second sensing unit in the thirdstate, and second reference capacitance between the second sensing unitand the first sensing unit in the fourth state; collect firstcapacitance between the first sensing unit and the second sensing unitin the third state, and second capacitance between the second sensingunit and the first sensing unit in the fourth state, calculate adifference of the first capacitance and the first reference capacitanceto obtain first capacitance difference, and calculate a difference ofthe second capacitance and the second reference capacitance to obtainsecond capacitance difference; calculate a difference of the firstcapacitance difference and the second capacitance difference to obtain acapacitance variation of the first sensing unit caused by touch;determine, according to the capacitance variation, the wearing state ofthe electronic device.
 6. The electronic device according to claim 5,wherein the detecting circuit is configured to: determine that thedevice is not worn if the capacitance variation is greater than or equalto a first preset threshold; determine that the device has been worn ifthe capacitance variation is smaller than or equal to a second presetthreshold; wherein the second preset threshold is smaller than the firstpreset threshold.